Message/Author 

cricket posted on Monday, May 24, 2004  8:59 am



When I run mixture models with all available data (e.g., type=mixture missing;), I get a likelihood ratio chisquare test for MCAR. However, I don't get that test when running ordinary LGM with (type = meanstructure missing h1). Is there any way to get that same test? 

bmuthen posted on Monday, May 24, 2004  9:57 am



You only get this test with categorical outcomes. 

cricket posted on Monday, May 24, 2004  10:07 am



I ran an LGM with my categorical outcome with the same instructions as above (i.e., analysis: meanstructure missing h1;), and I still didn't get the test. 


I should have said you only get this test with categorical outcomes and TYPE=MIXTURE not with an ordinary nonmixture growth model. You could use TYPE=MIXTURE and CLASSES = c (1); if you really want it. 

cricket posted on Monday, May 24, 2004  10:26 am



Thanks 


Is there information on the way that MPlus calculates its chisquare test of MCAR. I have looked through the manual and technical appendices, perhaps I have missed it. 


See Technical Appendix 6 formula 133. 

Jon Elhai posted on Sunday, June 15, 2008  9:12 am



Drs. Muthen, What is the command syntax for obtaining Little's MCAR test when using type=mixture? 


This is available only for categorical outcomes and is given automatically in this case. 

Tracy Witte posted on Wednesday, November 12, 2008  11:37 am



For the chisquare test for MCAR, I get a value of 111.37, df = 222, p = 1.0000 for the pearson & 85.65, df = 222, & p = 1.0000 for the likelihood ratio. Does this mean that MCAR does hold? Or do the p values of 1 mean that this test is uninterpretable? 


The discrepancy between the 2 chi2's probably indicate that neither is trustworthy due to many zero cells. 

Tracy Witte posted on Wednesday, November 12, 2008  1:42 pm



So should I just assume MAR to be safe? 


Yes. 

Aleksandra posted on Monday, December 08, 2008  8:34 pm



Dr. Muthien, what is the cost of specifying the data as MAR when the data are actually MCAR? Thank you very much. Alex 


There is no cost. When MCAR holds, MAR holds. 

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